/*
 * Copyright © 2012 The Feign Authors (feign@commonhaus.dev)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package feign.metrics4;

import com.codahale.metrics.MetricRegistry;
import feign.MethodMetadata;
import feign.Target;
import java.lang.reflect.Method;
import java.net.URI;
import java.net.URISyntaxException;

public final class FeignMetricName {

  private final Class<?> meteredComponent;

  public FeignMetricName(Class<?> meteredComponent) {
    this.meteredComponent = meteredComponent;
  }

  public String metricName(MethodMetadata methodMetadata, Target<?> target, String suffix) {
    return MetricRegistry.name(metricName(methodMetadata, target), suffix);
  }

  public String metricName(MethodMetadata methodMetadata, Target<?> target) {
    return metricName(methodMetadata.targetType(), methodMetadata.method(), target.url());
  }

  public String metricName(Class<?> targetType, Method method, String url) {
    return MetricRegistry.name(
        meteredComponent, targetType.getName(), method.getName(), extractHost(url));
  }

  private String extractHost(final String targetUrl) {
    try {
      return new URI(targetUrl).getHost();
    } catch (final URISyntaxException e) {
      // can't get the host, in that case, just read first 20 chars from url
      return targetUrl.length() <= 20 ? targetUrl : targetUrl.substring(0, 20);
    }
  }
}
